A polycarbonate resin is conventionally known as a resin having the highest impact-resistance of engineering plastics and having high heat resistance, and therefore, is used in various fields thanks to these advantages. However, the polycarbonate resin has drawbacks such as low chemical resistance, poor molding workability, and thickness dependence of impact strength.
Meanwhile, thermoplastic polyester resins have high chemical resistance and good molding workability, but have drawbacks such as low impact resistance and poor dimensional stability.
Various resin compositions have been proposed which utilize the advantages of these materials to compensate for their drawbacks. For example, attempts have been made to simultaneously satisfy impact resistance, heat resistance, chemical resistance, weather resistance, moldability, etc., that are required for automotive parts, etc.
At present, resin members that are formed as resin molded articles (also hereinafter simply referred to as “molded article”) are commonly substituted for metal members in various industrial fields. For example, for members, for electrical appliances, such as housings of mobile telephones and personal computers, and members, for vehicles, such as fenders, door panels, and rear door panels of automobiles, reduction in weight is strongly required, and a metal may be replaced by a resin in a larger area, and therefore, attempts have been made to increase the sizes of resin molded articles and decrease the thicknesses of shapes of molded articles by metal being replaced by resin. Increase of the size of the molded article and decrease of the thickness thereof require the use of a molding machine larger than conventional ones. Therefore, resins are likely to undergo thermal decomposition due to thermal hysteresis of the resins during molding, and shear heat generation during die filling, so that defective appearance (flash), etc., occurs on the molded article surface due to thermal decomposition gas. Flash is also called “silver” or “silver streaks.”
To reduce the thermal decomposition of a resin, Patent Literature 1 proposes a resin composition containing a polycarbonate resin, and a polyester-polyether copolymer modified with a polyalkylene glycol of a bisphenol, etc. The resin composition has excellent fluidity, and allows shear heat generation to be reduced even in a thin shape. Therefore, when the resin composition is used as a molding material, a large-sized or thin molded article can be obtained without defective appearance. However, under current circumstances that enhanced increase in sizes of molded articles and enhanced decrease in thicknesses thereof are required, and molded articles are expected to be used in environments having even higher temperature, etc., a resin composition that can be used to provide a molded article having enhanced heat resistance and thermal decomposition resistance is needed.